The present invention relates to a nut capable of being put into the tightening position on a threaded rod very easily and very quickly for the purpose of assembling together two pieces, and it is particularly, but not exclusively, intended for the building industry.
Pieces are very frequently fixed to together by one or more nut and threaded rod assemblies. The threaded rod may be constituted by a cylindrical rod having a thread over all or over a portion of its length or it may be constituted by a threaded cylindrical portion belonging to a more complex piece that is intended to withstand traction. The rod itself, or its cylindrical portion, need not be completely circular in section, and the circle representing the outside envelope of the thread in the section may be truncated by one or more flats of arbitrary shape. A rod of this type is referred to below as a "threaded rod".
In assemblies making use of threaded rods and nuts, since the threads on the rod and in the nut are engaged, it is necessary to rotate the nut to cause it to travel along the threaded rod until it comes into contact with the pieces to be assembled. This operation can be lengthly and difficult, particularly when access to the nut is difficult. An object of the present invention is to mitigate this difficulty and to provide a nut capable of being brought quickly into the clamping position. Proposals have already been made for such nuts.
FR-A-1 382 310 describes a high-speed clamping nut in which two partially tapped pieces are pivotally mounted inside a sliding ring in such a manner that in one position the nut can travel freely over the threaded rod, whereas in a second position of the pieces, the two tapped portions close together and engage the thread on the rod. It is thus the position of the ring which determines the state of the nut.
In U.S. Pat. No. 3,603,552, a nut for mounting scaffolding is constituted by two portions that are hinged to each other in such a manner that the internal tapping can be disengaged from the thread of the threaded rod over which it is to slide by means of handles.
However, without prohibitively increasing their dimensions, these nuts are incapable of counteracting large forces such as those which are encountered when assembling shuttering for casting concrete.
According to the present invention, a high-speed nut comprising two longitudinal pieces which are hinged to each other and which together define a central orifice having a first portion which is tapped and having a second portion which is substantially conical, the hinge axis of the two pieces being perpendicular to the axis of the central orifice, is characterized in that each of the pieces carries hinge means, clamping means, and mechanical connection means.
Thus, the two pieces constituting the nut are capable of pivoting about an external hinge disposed substantially one third of the way along their length to take up two positions: a first or "open" position in which the two portions constituting the tapping are spaced apart from each other, and a second or "closed" position in which the two portions are brought together to engage on the thread of the threaded rod. In the open position, the nut can travel freely over the threaded rod, e.g. by sliding linearly without rotating, thereby reaching its clamping position, and contact with the piece to be clamped automatically causes the nut to close. The object to be fixed is then clamped by rotating the nut through a few turns.
According to another characteristic of the invention, the hinge is constituted by two radial stub axles interconnected by rings.
Other characteristics and advantages appear from the following description of a particular embodiment, given purely by way of non-limiting example and made with reference to the drawings, in which: